Thermostatic control and signaling device



G. W. CRISE 2 Shasta-Sheet I,

THERMOSTATIC CONTROL AND SIGNALI NG DEVICE Filed Jan. 19, 1944 Sept. 7,1948.

Sept. 7, 1948.. G. w. ems:

v I THERMOSTAIIC CONTROL AND SIGNALING DEVICE 2 Sheets-Sheet 2 IIIG? 5.

Filed Jan 19, 1944 W 5-Hlgh Reslstqnc Lamp JYWW I George ri PatentedSept. 7, 194a ,rnnamos'mrrcconrnor. AND swarms I nnvroa orr cr.

George W. Crise, Columbus, Ohio f Application January 19,1944, SerialNo. 513,215:v

Y i This inventionrelates to thermostats of the yp employed in regulatinthe operation ofheating or air-conditioning systems, and the generalobject of the invention is to provide, in connection withsuchthermostats, a visual or audible signal which is adapted to beenergized, or to.

otherwise actively function, when'a critical condition prevails in theassociated heating or air.- conditioning apparatus.

An outstanding problem encounteredin heating systems e'quippedwithautomatic controls is that of when to refuel or otherwise attendthe fuelbed, and while this is particularly true of hand- 4 Claims. (CI. 177-311) lies in the fact that a signal which is frequently turned oil andon receives little attention, because of the repetitious nature of thecontrol, whereas,

in accordance with the present invention, my improvedsignaloperatesinfrequently and invariably represents a cause forconcern, requiring prompt correction of the condition indicated.-

For a further understanding of the invention, reference is to be had tothe following description and to the accompanying drawing, wherein:

Fig. 1 is a diagrammatic view of a fumacecontrolling thermostat andassociated draft-operating controls, wherein the thermostat is providedfired furnaces, it applie also to stoker-fed systems which necessitatethe removal of clinkers and ashes and the refilling of the stoker hopperwith coal.

In accordance with the'present invention, I minimize this problem bytheuse of a novel signal of an electrically energized type which operatesin conjunction" with a temperature regulating thermostat. so thatwhenever the room temperature fallsbelow a predetermined thermostaticsetting, the signal isenergized to warn the occu-.'

Pants of ahouse of the attention-requiring furnace condition.

with a visual warning signal. operated in accordance with the presentinvention;

Fig. 2 is a side elevational view,partly in vertical section, of thethermostatic switch disclosed In the past, some use has been made of asignal on a room thermostat for the purpose of indicating whether thedraft door offan' associated fur- Jiace was open, or that the stoker,oil or gas burner was functioning with its controls in an operatingposition, This information is, however, relatively unimportant, since itis the normal function of automatic controls toopen the'draft or effecta forced supply of fuel to the associated furnace or heater. Howevenitis important to know if the heating system needs personal attention orhas otherwise become inoperative so that theme may go out completely andrequire rebuilding. or. in the case of stokers, whether coal hasfouledithe feed screw, or if poor combustion has caused the fire in thefire bowl to go out, since in Fig.1;

Fig. 3 is a fragmentary front elevational view of a. modified form ofswitch;

Fig. 4 is a front elevational view of a still further modified form ofmy improved thermostatic switch:

Fig. 5 is an enlarged detail sectional view taken through the switchspring of the switch disclosed in Fig. 1 and the mounting therefor;

Fig. dis a wiring diagram of the electrical eircults involved in the useof the switch disclosed in Fig. 1; 4 a Fig. 7 is a similar view of theelectrical circuits employed in the switch structure of Fig. 4.

under these conditions, prolonged operation of" the stoker may fill thefurnace with unburned coal and evenbreak castings. In the case of an oilfire,clogging of the fuel nozzle and exhaustion 0f the oil supply arecommon onditions often encountered. In all thesecase s imp'ortant toknow at the earliest possible'imoment whether any of thesecontingencieshave-happened so thatthey may be corrected with the leasttrouble and before the house has become chilled. ,5,

"Another important advantageof my system,

Referring more particularly to the drawing, the

numeral Ill designates a furnace-controlling thermostat of thewall-mounted room type. Anassoelated remotely disposed furnace isindicated at Ii. the latter being shown as provided with a draft door I!which is adapted to be raised and lowered by a cable i3 extending over aguide I4 and around a motor-operated drum IS, the upper end of the cablebeing provided with ,a counterbalancing weight It. Used in operating thedrum ii is a shaded pole motor ll of the time disclosed in' my priorpatent, No. 2,134,685. While I may use other types of furnace controlactuators, such as relays. solenoids and the like. the shaded pole motorhere disclosed has been found to be par ticularly useful when employedin conjunction with my improved signallingmechanism, as will behereinafter more'fully set forth.

The motor II has a primary coil l..- which is adapted to be energized bybeing connected to any suitable source of alternating current. Thenumeral l9 designates fixed counter-clockwise shading coils, and thenumeral 20 wound clockwise shading coils which are adapted to be con- 3|extending from the terminal screw 33.

. 3 nected through leads 3| and 33 to terminal screws 33 and 34 of thethermostat l3.

It will benoted that the fixed shading coils l3 may possess sumcientcurrent capacity to cause a partial phase splitting. thereby causing thearmature 23 to rotate by the conventional shading coil method. The woundshading coils are of larger capacity, at least sufficient to overpowerthe en'ect -of the fixed coils l3 and cause reverse phase splittin withconsequent motor reversal when the circuit of said wound coils is closedby the action of the thermostat II.

It will be clear from the drawing that when the circuit through thethermostat is open, the circuit for said wound shading coils isinterrupted, thereby rendering the same inoperative and the direction ofrotation of the motonwill be determined by the action of the fixedshading coils in i which in a preferred embodiment, comprises a base 33'of an insulating material. This base carries a temperature regulatingindicator 31, the

hub of which is mounted for swinging movement about the longitudinalaxis of a stud shaft 33 carried in connectionwith the base 33, as shownin my prior patent, No. 2,336,387, issued January 2; 1945, the lower endof the indicator being movable with respect to a temperature raduatedsurface 33. Fixed to the studshaft 33 is the inner end of a spirallycoiled bimetallic element", the outer end of said element being free tomove in r sp nse to variations in adjacent temperatures.

"I'h'ebimetallic element is connected by aAlelagi the outer end of thebimetalli'celement is provided with acontact 33 which is adapted to bemoved into and out of engagement with a similar contact 33 carried bythe movable leg of a U-shaped metallic switch spring 34. This spring hasthe other or fixed leg th'ereof clamped between a pair of insulatingwashers 39 carried in connection withthe indicator arm 31. Axially,these washers are provided with an opening in which is fitted a sleeveof insulating material 40, the latter. being internally threaded for thereception of a. manually adiustablescrew 4|. The outer end of thisscrewis provided with a contact 43 which is disposed inregistration with asimilar contact 43 provided on the movable leg of the a spring 34 and inspaced relation from the contact sesses anadequate temperature, at orabove a predetermined normal, the free end of the bimetallic element isspaced from-the contact 33 of-the spring 34. thus allowing forengagement ofthe contacts 43 and 43,-as a result ofthe in- 1 h'erentresiliency of the spring. With the'partsof the-thermostat so positioned.the circuit of the woundshadingcoils ,33 is interrupted. However, as theroom in which the thermostat is positioned cools. the outer end of thebimetallic element, turning clockwise, strikes the contact 33. Atthismoment, and before separation 2. .2?

assure contacts 43 and 43, a primary circuit is made, current flowingthrough terminal 33 and conductor 3| to the bimetallic element, passingthrough contacts 33 and 33 and contacts 43 and 43 to the 6 adjustablescrew 4|, there being a conductor 43 uniting the screw 4i with theterminal 34, thus completing the primary circuit in which the woundshading coils are positioned. This reverses the operation of the shadedpole motor with re- 10 spect to that-which takes place'when the fixedcoils I. are fully effective, causing the opening of the furnacecontrols actuated thereby. When the area which the thermostat controlshas become satisfied with heat, as a result of the opening of thefurnace drafts or the like, the bimetallic element moves away from thespring contact 33, thereby interrupting the primary circuit in which thewound shading coils are positioned. causing the direction of the motorto reverse as a result of th'eexcitation of the fixed shading coils, and

closing the furnace controls.

The operation thus given is normal with the use of a shaded pole motorand a thermostat of the character set forth. However, assuming that whenthe thermostat operated to excite the wound shading coils, and therebycaused the opening of the furnace controls, for various reasons, such asthe furnace fire having been accidentally extinguished, the opening ofthe controls did not 0 result in the desired increase in temperature ofthe heated area, the present invention provides an automatic signal fordirecting attention to this undesiredcondition, and which is one whichthe thermostat and its associated parts cannot correct. Since theopening of the furnace controls did not result in the desired output ofheat, because of lack of'combustion or the like, the thermostaticelement 33 continues to turn in a clockwise direction as its surroundingtempera- 40"turefalls. This continued movement of the free current willflow from the bimetallic element and through the entire length of thespring 34. To the fixed end of the spring. which is clamped between theblocks or washers 38, there is joined a conductor 46 or conductors whichleads to the- 50 contact base 41 of an incandescent lamp 4|.

Another conductor 43 extends from the base 41 to the terminal 34. Thissignal lamp is positioned so that it may be readily seen by theoccupants of the dwelling in which the thermostat is arranged, and whenthe same illuminates, a

visual signal is thus made possible, notifying the h'ouse occupants atonce of the disorder in the heating system. The lamp. 43 may be disposedin a-relatively remote position with respect to the bimetallic element33, so that the heat of the lamp does not affect the bimetallic elementnor modify its operation, as shown in Fig. 1.

However. as shown in Fig. 3, if the lamp is disposed immediatelyadjacent tothe bimetallic ele- 6 ment. so that the heat of. the lamp isabsorbed at least in part by the bimetallic element, an operation isprovided inwhich the lamp 43:: will beintermittently energized when inits initial stages of operation, in order that its flashing may producea more effective visual signal than if the lamp were steadilyilluminated. This "flashing" ,is obtained by the fact that the heat ofthe lamp when applied to the bimetallic element will, at the earlystages of illumination of lamp, cause'flcxing of the bimetallic elementductor to reestablish engagement between the contacts I! and 43,providing at the beginning relatively long periods of deenergization ofthe lamp, which periods will gradually shorten'as the generaltemperature around the bimetallic element decreases until full andsustained energization of the lamp takes place.

While I have described and shown the signal as comprising anincandescent lamp, which is considered to be a preferred form, it willbe understood that an audible signal of anelectrically energized typemay be used in lieu-thereof.

It will be noted that the lamp 48 will be in cir cuit with and energizedby current flowing as generated by the shading coils of the motor l1,and, also, that the shading coils, due to the improved power factor ofthe resistance 01' the lamp, will be fully effectual; so that the motorwill have its full torque to lift the furnace damper l2, or to operateother similar combustion-promoting devices.

In the modified form of my improved thermostatic control, as shown inFig. 4, the thermostat comprises a dielectric base 50 which supports astud 5|.v Mounted on this stud for turn-' ing movement about itslongitudinal axis is a depending indicator arm 52, the lower'end of thelatter being movable adjacent a graduated surface 53 denotingtemperature. Connected with the stud 5! is the inner end of a bimetalliccoil 54, the latter having the same flexing characteristics in responseto temperature variations as the coil or element previously described.

The outer movable end of the coil or element 54 carries a contact 55which is adapted for engagement with a similar contact 55 carried by theouter end of a flexible switch reed 51. This reed has its opposite endsecured to an insulating block 58 supported in connection with the lowerend of the indicator arm 52. Also carried by the indicator arm is a pairof insulating washers 59 which effect the support of a manuallyadjustable screw 60. One end of this screw is provided with amanipulating head and at the opposite end thereof is arranged inregistration with the contact 56.

On the base 50, there is provided a terminal post 6| adapted forconnection with a conductor 82 which may lead to the motor ll, or otherelectrical device under control, such as a solenoid valve, relay or thelike. A conductor 63 extends from the post 6! to the terminal base 64ofa primary signal lamp 55. From the base 64, there extends a secondconductor 65 which leads to the fastenedend of the reed 51. The base 50is provided with a second terminal post This post is joined by aconductor 68 with the bimetallic element 54 and by another con ductor 69with the base of a secondary signalling lamp 10. From the base of thelamp 15, a conll extends to .the controlled electrical device. Theprimary signalling lamp 65 is' of the high resistance type, whereas thesecondary 6 are separated, so that no current passeslthrough either ofthe signalling lamps. As the temperature of the room cools, the flexingof the element 54 results in bringing the contacts 55 and 55 together.Under such conditions, a primary circuit is completed, current flowingfrom the post I through conductor 63 to the primary lamp 85, thence fromsaid latter lamp by way of conductor 65 to terminal post 12, throughconductor 13 and reed 51 to the contacts 55 and 55; thence through thebimetallic element 51 and through conductors 58 and 59, the secondarysignalling lamp Hi and conductor ll. When this circuit is completed, dueto difierences in the resistance values of the lamps 65 and 15, theprimary signal lamp will be energized to produce full illumination,whereas the secondary lamp will not be sufllciently energized to producean effective visual signal.

around the thermostat should continue to decrease even though undernormal actuation an increase in temperature should have resulted,

the continued deflection of the bimetallic element 55 in a clockwisedirection results in flexing the reed 51 to bring its contact 55 intoengagement with the inner end of the adjustable screw 50, thetemperature necessary for effecting such an engagement being variablethrough adjustment of the screw 60. When the contacts 55, 55

and are in mutual engagement a secondary circuitis completed and theprimary lamp 85 is short circuite'd, current flowing from the post: 6|through conductor H to the screw 55, thencethrough contacts and 55 tothe bimetallic element 54, passing from said element through thesecondary lamp HI and returning through conductors ll. Due to theincreased current values. produced as a result of the short circuitingof the primary lamp '5, suilicient current sirable for a thermostatused, for example, in

theaters or other public buildings, since the prisignalling lamp III isof'the low resistance type.

Preferably, the bulbs .of these lamps are of different colors, and whilethe lamps have been shown in closely assembled relation with thethermostat pro'per, it is understood that these lamps may be remotelydisposed with respect to each other, or with respect to the base of thethermostat, if desired.

In the operation of the mechanism disclosed in Fig] 4, when the room inwhich the thermostat is positioned possesses a temperature at orabove apredetermined normal, the contacts 55 and 56 'mary light can be set tooperate over any given temperature range, as for example, 4 degrees F.Any spread of, for instance, one-half to 10 degrees F. can be selectedby the adjustment of the thumb screw 50.

In this manner, a theater may be equipped. with a number of suchthermostats (Fig. 4)

placed within view of the operator, who could tell at a glance it allparts of a theater building were within the desired temperature limits.The secondary lamp 10 in this arrangement is used to indicate that thetemperature is below and not above the desired temperature. Preferably,the secondary lamp is of a different color from the main lamp so thatthe lamps may be distinguished at a distance. In case the thermostatproper could not be mounted in easy View temperature. Such anarrangement is 01' value If, for any reason, the temperature in the roomtors, brooders and the like. Any suitable power sup ly. such as a smalltransformer, may operate the thermostats in case no motor operation isnecessitated, as in Fig. 1.

While-I have described what I consider to be Q certain preferredembodiments of my improved signalling thermostat, nevertheless, it willbe understood that such embodiments are subject to further variation andmodification without departing necessarily from the scope of theappended claims.

Iclaim:

1. Temperature-controllingand indicating apparatus comprising a base,spaced terminals on said base adapted for connection with conductorsforming a circuit in which is located an associated electricallyoperated heater controiunit, a bimetallic element on said baseelectrically connected with the first or said terminals, said.

' electrically energized signal, a conductor leading-from the fixed ar-moi said 'switch member. to said signal andfrom the latter to the secondof said terminals, whereby extreme deflection of said. bimetallicelement produces fiexure oi'the movable arm' of said switch member toseparate the same from said adjustable contact and thereby divertcurrent flow through said signal.

2-. Temperature-controlling apparatus comprising a base, a pivotallymovable indicator mounted on said base, a spirally coiled bimetallicelement having the inner end thereof joined with said base adjacent thepivotal axis of said indicator,

7 I the free'end of said element being defiectable in response totemperature variations, a resilient ii -shaped switch member having astationary arm anda movable arm, the fixed arm of said switch memberbeing mounted, in connection with said indicator and the movable armthereof being arranged in the path of movement of the free end of saidbimetallic element, an adjustable contact carried by said indicator andnormally disposed in engagement with the resilient arm of the switchmember, continued cooling ofsaid bimetallic element serving to memberfrom said contact.

remove said switch member from circuit-com- 3. Temperature-controllingand indicatingapparatus comprising a base, a stud on said base,

a temperature indicator mounted at one end i on said stud for pivotalmovement in a plane parallel with the base, a spirally coiled bimetallicelement having its inner end fixed to said'stud,

the outer end oi said element being free to defleet in response tosurrounding temperature variations, a resilient switch arm fixed at oneend to said indicator and having its other end disposed for resilientengagement with the outer deilectable end 01. said bimetallic element, athreadedly adjustable contact member carried by said indicator forengagement with the resiliently movable portion 01 said switch arm, amain control circuit including a pair of conduetors, one of saidconductors leading to said bimetallic element and the other to theadjust-' able contact member, and a supplemental signalcontrollingcircuit automatically completed when said bimetallic element isabnormally deflected in I on said base, a spirally coiled bimetallicelement having the inner end thereof "joined with said base adjacent tothe pivotal axis of said indicator, the free end oi said element beingdefiectable in response to temperature variations, a resilient switcharm fixed at one end to said indicator and having its other end disposedin the path of movement of the outer defiectable end of said bi-metallicelement, an adjustablecontact car-- ried by saidindicator forcircuit-completing engagement with the resiliently movable portion oisaid switch arm, a main control circuit including a pair of conductors,one of which leads to the bimetallic element and the other to theadjustable contact member, whereby when said bimetallic element isdeflected in a circuit-closing direction to initially engage said switcharm said circuit is closed, and a supplemental signal controllingcircuit completed when said bimetallic element is abnormally deflectedin its circuit- P closing direction and following closure of said maincircuit.

GEORGE w. muss.

I REFERENCES crr'izp v The following references are of record in thefile of this patent:

-- UNITED STATES PATENTS Burch June 18, 1946

